From twalters@virage.com

Created by twalters@virage.com

The following command causes perl to hang for a long time, adding lots
of undefs to a nested array​:

perl -e 'use Data​::Dumper; $h->{r} = [{a=>[{},{}]},{a=>[{}]}]; print
Dumper($h);$h->{r}->{a}="d";print Dumper($h)'

# Outputs​:

$VAR1 = {
  'r' => [
  {
  'a' => [
  {},
  {}
  ]
  },
  {
  'a' => [
  {}
  ]
  }
  ]
  };

# After a wait of several minutes the modified array is written....

$VAR1 = {
  'r' => [
  {
  'a' => [
  {},
  {}
  ]
  },
  {
  'a' => [
  {}
  ]
  },
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
  undef,
[ ... continues indefinitely ... ]

Site configuration information for perl 5.00503:

Configured by twalters at Wed Dec 22 14:11:37 PST 1999.

Summary of my perl5 (5.0 patchlevel 5 subversion 3) configuration:
  Platform:
    osname=solaris, osvers=2.7, archname=sun4-solaris
    uname='sunos tokyo 5.7 generic sun4u sparc sunw,ultra-2 '
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=undef useperlio=undef d_sfio=undef
  Compiler:
    cc='cc', optimize='-fast', gccversion=
    cppflags=''
    ccflags =''
    stdchar='char', d_stdstdio=define, usevfork=false
    intsize=4, longsize=4, ptrsize=4, doublesize=8
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16
    alignbytes=8, usemymalloc=y, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =''
    libpth=/usr/local/lib /lib /usr/lib /usr/ccs/lib
    libs=-lsocket -lnsl -ldl -lm -lc -lcrypt
    libc=/lib/libc.so, so=so, useshrplib=false, libperl=libperl.a
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags=' '
    cccdlflags='-KPIC', lddlflags='-G'

Locally applied patches:



@INC for perl 5.00503:
    /export/home2/twalters/Dev/Apps/VSS/lib
    /virage/people/twalters/lib/blib/lib
    /virage/people/twalters/lib/blib/arch
    /usr/local/lib/perl5/5.00503/sun4-solaris
    /usr/local/lib/perl5/5.00503
    /usr/local/lib/perl5/site_perl/5.005/sun4-solaris
    /usr/local/lib/perl5/site_perl/5.005
    /usr/local/lib/perl5/5.00503/sun4-solaris
    /usr/local/lib/perl5/5.00503
    /usr/local/lib/perl5/site_perl/5.005/sun4-solaris
    /usr/local/lib/perl5/site_perl/5.005
    .


Environment for perl 5.00503:
    HOME=/virage/people/twalters
    LANG (unset)
    LANGUAGE (unset)

LD_LIBRARY_PATH=/export/home2/twalters/Dev/Local-lib/debug/solaris:/usr/local/lib:/export/home2/twalters/Dev/Local-lib/debug/solaris:/usr/local/lib:/export/home2/twalters/Dev/Local-lib/debug/solaris:/usr/local/lib:/export/home2/twalters/Dev/Local-lib/debug/solaris:/usr/local/lib:/export/home2/twalters/Dev/Local-lib/debug/solaris:/usr/local/lib::/usr/openwin/lib:/opt/SUNWits/Graphics-sw/xil/lib:/usr/galaxy/lib

    LOGDIR (unset)

PATH=/virage/people/twalters/bin:/export/home2/twalters/Dev/bin:/virage/people/twalters/bin:/virage/people/twalters/bin:/virage/people/twalters/bin:/virage/people/twalters/bin:/virage/bin/solaris:/virage/bin:/usr/local/bin/:/usr/bin:.:/usr/etc:/opt/SUNWspro/bin:/usr/ccs/bin:/usr/openwin/bin:/usr/sbin:/usr/ucb:/usr/local/illustra/bin:/usr/local/3dviewnix/PROCESS/BIN

PERLLIB=/export/home2/twalters/Dev/Apps/VSS/lib:/virage/people/twalters/lib/blib/lib:/virage/people/twalters/lib/blib/arch:/usr/local/lib/perl5/5.00503/sun4-solaris:/usr/local/lib/perl5/5.00503:/usr/local/lib/perl5/site_perl/5.005/sun4-solaris:/usr/local/lib/perl5/site_perl/5.005

    PERL_BADLANG (unset)
    SHELL=/bin/tcsh

From @gsar

On Wed, 22 Mar 2000 14​:37​:58 PST, Tim Walters wrote​:

The following command causes perl to hang for a long time, adding lots
of undefs to a nested array​:

perl -e 'use Data​::Dumper; $h->{r} = [{a=>[{},{}]},{a=>[{}]}]; print
Dumper($h);$h->{r}->{a}="d";print Dumper($h)'

  % perl5.6.0 -we '$h->{r} = [{a=>[{},{}]},{a=>[{}]}]; $h->{r}->{a}="d";'
  Out of memory!

Data​::Dumper is not involved here. Perl thinks you're accessing the
pseudo-hash element in $h->{r}[ $h->{r}[0]{a} ]. And of course,
$h->{r}[0]{a} amounts to a "numeric" value of 0xfeedface or thereabouts.
You know the rest.

We really oughtta croak on seeing an index that's a reference, but it
needs some care, or bigints etc won't work right.

Sarathy
gsar@​ActiveState.com

From @floatingatoll

[RT_System - Wed Mar 22 08​:28​:47 2000]​:

On Wed, 22 Mar 2000 14​:37​:58 PST, Tim Walters wrote​:

perl -e 'use Data​::Dumper; $h->{r} = [{a=>[{},{}]},{a=>[{}]}]; print
Dumper($h);$h->{r}->{a}="d";print Dumper($h)'

% perl5.6.0 -we '$h->{r} = [{a=>[{},{}]},{a=>[{}]}]; $h->{r}->{a}="d";'
Out of memory!

[...]

We really oughtta croak on seeing an index that's a reference, but it
needs some care, or bigints etc won't work right.

As of the perl 5.8/5.9 development track, this code now throw the error "Not a
HASH reference", for both provided examples. I'm resolving this issue; thanks
for the bug report!

- R.

$VAR1 = {
  'r' => [
  {
  'a' => [
  {},
  {}
  ]
  },
  {
  'a' => [
  {}
  ]
  }
  ]
  };
Not a HASH reference at -e line 2.

@floatingatoll - Status changed from 'open' to 'resolved'